(i) Technical Field
The present invention relates to a post-processing apparatus.
(ii) Related Art
In a post-processing apparatus that performs post-processing, such as stapling or punching, on a recording medium, such as a printing sheet, on which a printing operation has been performed, plural printing sheets on each of which the post-processing is to be performed are stored in a storing unit called a compilation tray, and then the post-processing is performed on the stored printing sheets.
A member that has a paddle-like shape and includes blades is used as a transport member that transports a printing sheet to such a compilation tray.
Here, in the case of not performing post-processing on printing sheets and in the case of ejecting a stack of printing sheets that are produced by performing stapling on plural printing sheets stored in the compilation tray, the printing sheets are ejected to an ejection tray or the like by passing through the location at which the transport member is disposed.
Accordingly, there is a case where switching control for causing the transport member to move downward when a printing sheet is to be transported to a storing unit, such as the compilation tray, and to move upward when a printing sheet or a stack of printing sheets is caused to pass through the location at which the transport member is disposed is performed.
There is also a configuration in which such switching control for causing the transport member to move upward and downward does not need to be performed and in which the center of rotation of the transport member does not move upward and downward. However, in the case where such a configuration is employed, the distance from the center of rotation of the transport member to a printing sheet becomes large, and it is necessary to increase the lengths of the blades of the transport member.
In the case where each of the blades of the transport member is formed of a member whose end portion and bottom portion have the same strength and where the length of each of the blades is increased, it is difficult to secure a necessary transport force, and there is a possibility of insufficient transport force.
Accordingly, forming each of the entire blades out of a member having a large strength may be considered. However, if such a configuration is employed, contrary to the above, the transport force becomes excessively large, and the probability of occurrence of a paper jam increases.